Late stage assay provider results from the probe development effort to identify inhibitors of DAGLb: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) assay to distinguish systemic and peripheral inhibitors
Name: Late stage assay provider results from the probe development effort to identify inhibitors of DAGLb: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) assay to distinguish systemic and peripheral inhibitors. ..more
BioActive Compound: 1
Depositor Specified Assays
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center (SRIMSC)
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Benjamin Cravatt, The Scripps Research Institute (TSRI)
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: 1 R01 DA025285
Grant Proposal PI: Benjamin Cravatt, The Scripps Research Institute (TSRI)
External Assay ID: ABHD6_INH_FLUO_2X%INH_INVIVO_PERIPHERAL
Name: Late stage assay provider results from the probe development effort to identify inhibitors of DAGLb: fluorescence-based biochemical gel-based competitive Activity-Based Protein Profiling (ABPP) assay to distinguish systemic and peripheral inhibitors.
Endocannabinoids (ECs) represent a unique group of lipids that function as chemical messengers in the nervous system. To date, the two principle ECs identified in mammals are N-arachidonoyl-ethanolamine (anandamide) and 2-arachidonoyl-glycerol (2-AG). They have been implicated in various physiological and pathological functions including appetite, pain, sensation, memory, and addiction (1). Unlike traditional neurotransmitters, which are stored in vesicles, ECs are synthesized and released on demand, and then rapidly degraded to terminate signaling. Thus, the metabolic pathways that govern EC turnover are critical in determining the magnitude and duration of neuronal signaling events (2). Endocannabinoid biosynthesis, in contrast to degradation, is poorly understood. Recently, two serine hydrolases, DAGL-a and -B, were cloned and found to selectively cleave sn-1 acyl chains from diacylglycerols (DAG) to generate 2-AG in vitro (3). Their function in the nervous system was validated in vivo by the generation of DAGL-a and DAGL-B knock-out mice (4, 5). However, it is still unclear to what extent DAGL-a/B catalytic activity contributes to 2-AG-mediated signaling. The development of potent and selective inhibitors would offer a means to perturb DAGL-a/B activity in a selective, reversible, and temporally-controlled manner. Given the non-selective nature of current DAGL-a/B inhibitors (6), specific chemical probes would serve as invaluable tools to delineate DAGL-a/B function in 2-AG signaling networks of the brain.
1. Di Marzo, V. (2008) Targeting the endocannabinoid system: to enhance or reduce?, Nat Rev Drug Discov 7, 438-455.
2. Ahn, K., McKinney, M. K., and Cravatt, B. F. (2008) Enzymatic pathways that regulate endocannabinoid signaling in the nervous system, Chem Rev 108, 1687-1707.
3. Bisogno, T., Howell, F., Williams, G., Minassi, A., Cascio, M. G., Ligresti, A., Matias, I., Schiano-Moriello, A., Paul, P., Williams, E. J., Gangadharan, U., Hobbs, C., Di Marzo, V., and Doherty, P. (2003) Cloning of the first sn1-DAG lipases points to the spatial and temporal regulation of endocannabinoid signaling in the brain, J Cell Biol 163, 463-468.
4. Gao, Y., Vasilyev, D. V., Goncalves, M. B., Howell, F. V., Hobbs, C., Reisenberg, M., Shen, R., Zhang, M. Y., Strassle, B. W., Lu, P., Mark, L., Piesla, M. J., Deng, K., Kouranova, E. V., Ring, R. H., Whiteside, G. T., Bates, B., Walsh, F. S., Williams, G., Pangalos, M. N., Samad, T. A., and Doherty, P. (2010) Loss of Retrograde Endocannabinoid Signaling and Reduced Adult Neurogenesis in Diacylglycerol Lipase Knock-out Mice, J Neurosci 30, 2017-2024.
5. Tanimura, A., Yamazaki, M., Hashimotodani, Y., Uchigashima, M., Kawata, S., Abe, M., Kita, Y., Hashimoto, K., Shimizu, T., Watanabe, M., Sakimura, K., and Kano, M. (2010) The Endocannabinoid 2-Arachidonoylglycerol Produced by Diacylglycerol Lipase +/- Mediates Retrograde Suppression of Synaptic Transmission, Neuron 65, 320-327.
6. Hoover, H. S., Blankman, J. L., Niessen, S., and Cravatt, B. F. (2008) Selectivity of inhibitors of endocannabinoid biosynthesis evaluated by activity-based protein profiling, Bioorganic & Medicinal Chemistry Letters 18, 5838-5841.
late stage, late stage AID, assay provider, powders, counterscreen, diacylglycerol lipase, diacylglycerol lipase-beta, DAGL, DAGL-beta, DAGLB, hydrolase, serine hydrolase, appetite, pain, sensation, memory, addiction, abhydrolase domain containing protein 6, ABHD6, activity-based protein profiling, ABPP, gel-based, activity-based probe, HT-01, inhibitor, inhibition, peripheral, in vivo, Scripps, Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN
§ Panel component ID.
The purpose of this assay is to determine the bio-distribution of powder samples of test compounds in vivo. In this assay, test compounds are administered to mice. Mice are sacrificed, and their brain and liver tissue harvested, homogenized, and the membrane fractions isolated and reacted with the activity-based probe HT-01. HT-01 bears a BODIPY fluorophore and urea triazole reactive group that selectively labels several serine hydrolases. This reagent is used instead of either the standard serine-hydrolase-specific activity-based probe fluorophosphonate-rhodamine (FP-Rh) to enhance visualization of select targets, which is otherwise obscured by other serine hydrolases upon SDS-PAGE separation/visualization. The reaction products are separated by SDS-PAGE and visualized in-gel using a flatbed fluorescence scanner. The percentage activity remaining is determined by measuring the integrated optical density of the bands. As designed, test compounds that act as inhibitors will prevent enzyme-probe interactions, thereby decreasing the proportion of bound fluorescent probe, giving lower fluorescence intensity in the band in the gel.
Purpose-bred C57-black laboratory mice were administered test compound (1, 0.5, or 0.1 mg/kg in 18:1:1 saline:PEG300:EtOH vehicle solution, i.p.) or vehicle only (n=2 per group). After 4 hours, mice were humanely sacrificed (anesthetized with isoflurane and decapitated) and brain and liver tissue was removed and snap frozen in liquid nitrogen. Tissues were homogenized and the membrane fraction isolated by centrifugation (45 min, 100K x g) and adjusted to 1 mg/mL in DPBS. Aliquots (50 uL) were reacted with the activity-based probe HT-01 (1 uL of a 50x stock in DMSO, 1 uM final concentration) for 30 minutes at 37 C. The reactions were quenched with an equal volume of 2x SDS-PAGE loading buffer (reducing), separated by SDS-PAGE and visualized by in-gel fluorescent scanning. The percentage activity remaining was determined by measuring the integrated optical density of test compound bands relative to vehicle bands. For this assay, only inhibition of anti-target ABHD6 was used as a diagnostic for observing inhibition due to the weak and diffuse nature of the DAGLb band.
The % inhibition was then calculated as follows:
%_Inhibition = ( 1 - ( IOD_Test_Compound - Median_IOD_Low_Control ) / ( Median_IOD_High_Control - Median_IOD_Low_Control ) ) * 100
Test_Compound is defined as ABHD6 treated with test compound.
High_Control is defined as ABHD6 treated with DMSO only (no compound).
Low_Control is defined as background in a blank region of the gel.
PubChem Activity Outcome and Score:
The following applies to each panel in this assay:
Compounds with greater than or equal to 50% inhibition at 0.1 mg/kg cpd were considered active. Compounds with less than 50% inhibition at 0.1 mg/kg cpd were considered inactive.
The reported PubChem Activity Score has been normalized to 100% of the observed value at 0.1 mg/kg.
Brain Tissue Score: The PubChem Activity Score range for active compounds is 100-100, and for inactive compounds 10-10.
Liver Tissue Score: The PubChem Activity Score range for active compounds is 100-86. There are no inactive compounds.
Overall Outcome and Score:
Compounds active in both assays were considered active (systemic inhibitors). Compounds inactive in the brain inhibition assay but active in the liver assay were considered inactive (peripheral inhibitors).
The PubChem Activity Score is assigned a value of 100 for active compounds, and 0 for inactive compounds.
The PubChem Activity Score range for active compounds is 100-100, and for inactive compounds 0-0.
List of Reagents:
C57-black laboratory mice (provided by Assay Provider)
HT-01 (provided by Assay Provider)
DPBS (Cellgro 20-031-CV)
This assay was performed by the assay provider with powder samples of synthetic compounds.
BAO: version: 1.4b1090
BAO: bioassay specification: assay stage: secondary: counter screening
BAO: bioassay specification: assay biosafety level: bsl1
BAO: assay format: biochemical format: protein format: single protein format
BAO: bioassay specification: assay measurement type: endpoint assay
BAO: bioassay specification: assay readout content: assay readout method: regular screening
BAO: bioassay specification: assay readout content: content readout type: single readout
BAO: meta target: molecular target: protein target: enzyme: generic hydrolase
BAO: meta target: biological process target: regulation of molecular function
BAO: meta target detail: binding reporter specification: interaction: protein-small molecule
BAO: detection technology: fluorescence: fluorescence intensity